The Thennanin are an incredibly alien telepathic race who are unable to communicate with 99% of other species, except through math and pictures, when they bother to try. Their civilization is highly advanced, especially in star drives and the biosciences. They are also a hostile race that has conquered many neighboring alien species and destroyed several others, including the ancient Castax Imperium and the Primisaurr Empire. When encountering a race that effectively resists their expansion into space, the Thenannin dust the planets infested with the alien species with bioagents, wiping them out. They are a grim conquering force that luckily despises the Atorian Empire and are preparing for conflict with them.